This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Advanced microscopy techniques represent major investigational approaches in each of the proposed projects of our multi-disciplinary program. The choice of the most appropriate method can be very complex, and the techniques involved in sample preparation require considerable skill. Therefore the In Vitro Microscopy Core will play a particularly important role in this collaborative program. The Core will provide state-of-the-art expertise in various steps of the projects, from experimental design and specimen preparation, to image capture and analysis of high-resolution light and electron micrographs. The In Vitro Microscopy Core will be based in the recently established Imaging Facility of the Cardiovascular Biology Research Program, under the direction of Dr. Florea Lupu. An experienced imaging specialist, Dr. Andrew Westmuckett will devote 50% of his effort towards the activities described in this proposal. The core has the expertise and the equipment to perform a diversity of techniques, ranging from brightfield histological analysis to confocal microscopy and 3D imaging, from standard transmission electron microscopy to immunogold labeling and advanced cryo-technologies (cryoimmunogold labeling, freeze substitution, high pressure freezing, and freeze fracture and deep-etching).